Read Obama's Speech

President Obama tackled the divisive issue of abortion this past weekend, urging people on all sides of the debate to seek common ground. But less noteworthy than what he said is where he said it: the University of Notre Dame. The Roman Catholic institution had drawn criticism for inviting the president, whose support for abortion rights is at odds with church doctrine.

Obama said even though supporters and opponents of abortion rights may have "irreconcilable" differences, the two camps should still treat one respectfully, with what he called "open hearts and open minds."

"Maybe we won't agree on abortion, but we can still agree that this heart-wrenching decision for any woman is not made casually," Obama said. "So let us work together to reduce the number of women seeking abortions." He suggested work on reducing unintended pregnancies, encouraging adoption and supporting pregnant women.

Obama urged the same kind of cooperation on other divisive issues, saying the challenges now facing the planet are too big for one person, one nation or even one faith to tackle individually.

"We must find a way to reconcile our ever-shrinking world with its ever-growing diversity – diversity of thought, diversity of culture and diversity of belief. In short, we must find a way to live together as one human family," he said.

The president got several standing ovations from the graduates and their families.

Although his speech was interrupted several times by anti-abortion hecklers, they were quickly shouted down. Even those who disagreed with the president on abortion, like Michelle Coble, were generally respectful. The architecture student wore a model of the Supreme Court building on her mortarboard, along with a sign saying "Fight for Unborn Human Rights."

Coble said she thought Obama found a good "middle ground" in his speech.

A few rows away, graduate Katie Michel was even more enthusiastic. Michel, who is not Catholic, wore a sticker that read "Pro Obama, Pro Choice."

"I really like that he addressed the big white elephant in the room head on and said, 'we're going to talk about this,' " Michel said. "It's something that has been important to our class."

Protests against Obama's visit spilled outside the university, as anti-abortion activists tried to draw attention to their cause. Hundreds of demonstrators gathered at the school's main gate, and a few dozen were arrested for trespassing on campus.

Notre Dame President John Jenkins said while much of the focus was on the risk the university took in inviting Obama, few paid attention to the risk the president took by accepting.

"Others might have avoided this venue. But President Obama is not someone who stops talking to those who differ with him," Jenkins said.

Obama spoke approvingly of Notre Dame's emeritus president, Ted Hesburgh, who argued that the university should be "both a lighthouse and a crossroads," standing up for its Catholic principles but not shunning those with differing views.

The president also recalled the key role Hesburgh played on an Eisenhower-era Civil Rights Commission that included members who were black and white, Republican and Democrat, and Northern and Southern.

"Years later, President Eisenhower asked Father Ted how on Earth he was able to broker an agreement between men of such different backgrounds and beliefs," Obama said. "And Father Ted simply said that during their first dinner in Wisconsin, they discovered that they were all fishermen. And so he quickly readied a boat for a twilight trip out on the lake. They fished, and they talked, and they changed the course of history."

Obama urged graduates to remember that when they face their own daunting challenges. "In the end," he said, "we are all fishermen."